Historically, there have been two main ways to receive audio tracks. If a user purchases a physical medium that stores the audio tracks, then the user has complete control over what tracks to play and when to play them. However, a physical medium (such as a CD) has a fixed set of audio tracks, such as a specific “album” from a single artist. With more work, a user can “burn” additional physical media that have customized sequences of audio tracks. However, even with that work, the list is still fixed.
An alternative is to listen to audio tracks on a radio station. A radio station has a very large selection of audio tracks and can play those tracks in an endless variety of sequences. In addition, different radio stations can focus on different genres, enabling users to select the specific type of music desired (which can vary from day to day or from hour to hour). However, radio stations have a different set of problems. One problem is the abundance of commercials and other interruptions. A second problem is that the selected audio tracks may not be of interest to the listener. In fact, a user may strongly dislike some of the audio tracks that are played. A user can address these problems to some extent by switching the station or channel. However, the need to switch among multiple stations or channels may indicate that there is no station or channel that is a good match for a specific user's interests.
Some companies have addressed these problems by providing streaming content over the Internet. In some instances, a user searches for desired content items (e.g., audio tracks), and the desired content items are subsequently streamed to the user over a computer. Some websites provide Internet radio stations, which can be designated for a single individual or group of individuals. The Internet radio stations stream an endless sequence of content items, commonly without commercials. In addition, if a user does not want the current content item, the user can execute a “skip-forward,” which prompts the Internet radio station to select and stream a new content item.
Despite the appeal of an Internet radio station as described, there are still problems. One problem is how to select content items that best represent what a user wants. This is particularly difficult when the Internet radio station has little information about a user's preferences. Furthermore, some users are reluctant to spend their time giving extensive information about their preferences.
In addition, many users like to listen to a radio station with a specific genre. Historically, a DJ or other individual would select content items corresponding to an identified “genre”. However, different individuals may have different opinions, and some of those opinions may not correspond to what people expect. Also, even if there is common knowledge about the classification of some content items, it may not be possible to identify that common knowledge. As with person preferences, users are typically reluctant to spend their time providing explicit feedback.